go to a bike store
you can;t get anything decent at walmart or target
or online, unless you can also assemble and tune it
entry level road bikes are pretty good
i happen to like fuji
others will all be in the same ball park of goodness at a given price
400 isn;t enough really
you could get a hybrid MAYBE on sale
sizes vary, unfortunately
one company;s L is another;s XL
even the numbered ones, 54cm, 56cm, etc are not standard
you probably want 58 cm in a road bike
but you ahve to try it
bike stores will get you the right size
there are no special ''weather'' or ''outside bikes''
any bike in that range will have quick release wheels
wle